In order to make aircraft passengers comfortable, and in order to transport them between an airport terminal building and an aircraft in such a way that they are protected from weather and other environmental influences, passenger boarding bridges are used which can be telescopically extended and the height of which is adjustable. For instance, an apron drive bridge in present day use includes a plurality of adjustable modules, including: a rotunda, a telescopic tunnel, a bubble section, a cab, and elevating columns with wheel carriage. Manual, semi-automated and fully-automated bridge alignment systems are known for adjusting the position of the passenger boarding bridge relative to an aircraft, for instance to compensate for different sized aircraft and to compensate for imprecise parking of an aircraft at an airport terminal.
Automated bridge alignment systems provide a number of advantages compared to manual and semi-automated systems. For instance, automated bridge alignment systems do not require a human operator, and therefore the costs that are associated with training and paying the salaries of human bridge operators are reduced. Furthermore, an automated bridge alignment system is always standing by to control the passenger boarding bridge as soon as an aircraft comes to a stop. Accordingly, delays associated with dispatching a human operator to perform a bridge alignment operation are eliminated, particularly during periods of heavy aircraft travel.
Of course, automated bridge alignment systems require accurate and precise identification regarding the position of the doorway to which the passenger boarding bridge is to be aligned. It is a disadvantage of known automated bridge alignment systems that environmental conditions, surface marking of the aircraft, incorrect identification of aircraft model, etc. may make it impossible to identify the doorway position to within a predetermined tolerance for error. In such a case, typically it is necessary to dispatch a human bridge operator to complete the alignment operation in a manual fashion. Unfortunately, when automated bridge alignment systems are used routinely, an airport is likely to maintain only a relatively small pool of human operators on call. When the doorway position cannot be determined, unacceptable delays are expected due to the time that is required for a bridge operator to become available and arrive at the passenger boarding bridge. In addition, manual bridge alignment typically requires more time to perform than does automated bridge alignment, which adds further to the delay. Such delays not only inconvenience passengers, but they also affect flight scheduling and scheduling of ground service resources at the gate.
It would be advantageous to provide a system and method that overcomes at least some of the above-mentioned limitations of the prior art.